Looptakers and thread case construction



P 24, 1963 J. R. IOANNILLI 3,104,634

LOOPTAKERS AND THREAD CASE CONSTRUCTION Filed May 3, 1962 s Sheets-SheetI P 1963 J. R. IOANNILLI LOOPTAKERS AND THREAD CASE CONSTRUCTION 3Sheets-Sheet 2 Filed May 3, 1962 Sept. 24, 1963 J- R. lOANNlLLI3,104,634

LOOPTAKERS AND THREAD CASE CONSTRUCTION Filed May 5, 1962 3 Sheets-Sheet3 56\& m2

United States Patent 3,194,634 LOOPTAKERS AND THREAD CASE CUNSTRUCTIONJoseph R. Ioannilli, Beverly, Mass, assignor to United Shoe MachineryCorporation, Boston, Mass, 21 corporation of New Jersey Filed May 3,1962, Ser. No. 192,250 8 Qiaims. (til. 11238) This invention relatesgenerally to improvements in lock stitch shoe outsole sewing machines orstitchers and more particularly to an improved looptaker and lockingthread case construction for such machines.

A well known form of outsole stitcher comprises a curved hook needle anda looptaker in the form of a rotary hook for casting loops of threadwithdrawn from the work by the needle about a stationary locking threadcase inside the rotary hook to form stitches. In the conventional formof stitcher the rotary hook is journaled in a split raceway and drivenby gears two or three revolutions during each sewing cycle. The threadcase is retained against rotation by a pair of alternately engagingreciprocating pins slidable in a stationary casing The pins enternotches in the thread case and are alternately withdrawn to permitpassage of the needle loop. The rotary hook and thread case constructionincluded in such conventional stitchers suffers from inadequatelubrication, an excessive rate of wear, noisy operataion and mostimportantly, a limitation on sewing speeds.

An important object of the present invention is accordingly to increaseattainable sewing speeds of outsole stitchers.

A related object is to extend substantially the useful life of outsolestitchers operated at higher speedsthan have heretofore been attained.

Another object is to achieve economy in the manufacture of outsolestitchers by reducing the number and complexity of especially producedcomponent parts.

Still another object is the reduction of noise and vibration attendingthe high speed operation of outsole stitchers.

An important object is to improve the manner in which the needle threadis handled by the thread manipulating instrumentalities of stitchers sothat the thread is not unduly weakened during stitch formation.According to a feature of the present invention the locking thread caseis retained against rotation by a nose connected to the case by areleasable detent. The nose is engaged by a fixed abutment member and asa result movingretainers such as the reciprocating pins described inconnection with conventional machines are thus entirely eliminated. Thenose is formed with a surface over which the thread passes as the needleloop is being expanded by the rotary hook. The contour of the nose isalso such that it. defines with the abutment member a tapered passageinto which one leg of the needle loop is guided during expansion of theneedle loop with minimum abrasion and stress being applied to thethread. The detent connecting the nose to the thread case is releasableto permit the thread case to revolve with the rotary hook without damagein the event that lint and thread fiber accumulations or otherobstructions cause binding together of the hook and case.

Cooperating with the featured retainer arrangement is an improvedmounting and drive for the rotary hook according to another feature ofthe invention. In the present machine the rotary hook is mounted on ballbearings and driven with little noise or vibration in timed relationwith other instrumentalities of the machine by a flexible cogged belt.The combination of the improved mounting and drive for the rotary hookgreatly enhances the performance of the .thread case retainer con- IceThe objects and features as Well as numerous advantages of the presentinvention will be realized from a detailed description of anillustrative embodiment taken in connection with the accompanyingdrawings in which,

'FIG. 1 is a fragmentary view in front elevation of an outsole stitcherincluding a threadcase and rotary hook mounted and driven according tothe present invention;

FIG. 2 is a View in cross section taken along the line II-II of FIG. -1and particularly depicting details of the rotary hook drive;

FIG. 3 is a view of parts of the rotary hook and locking thread caseshown in FIGS. 1 and 2, here depicted in exploded relationship;

FIG. 4 is a view of the rear of the rotary hook and thread case assemblyof FIG. 3, as viewed from the didirection of the arrow IV of FIG. 3; and

FIG. 5 is a viewof the side of the thread case in which the rotary hookand thread case retainer abutment are fragmentarily illustrated in crosssection.

The present invention is embodiedin a machine comprising a frame 10shown fragmentarily in FIGS. 1 and 2 in which is journaled a sewingshaft 12 for operating Work feeding and stitch forming instrumentalitiesof the machine. A work piece illustratedin FIG. 1 as consisting of anoutsole 14 and a welt 16 rests on a Work support 18 and is clamped by apresser. foot 20, the work support and presser foot comprising a workclamp while being pierced by an awl 22 to form an opening for a curvedhook needle 24. To form stitches the needle 24 penetrates through thework piece 14, 16 passing through an opening previously formed by theawl22 and is threaded by a looper 26 which has previously laid the needlethread indicated at 28 behind a thread finger 30 for thread storage tobe released later in the sewing cycle as the needle is withdrawn fromthe work. As the needle is being withdrawn the loop of thread which itcarries is opened by a loop spreader 32 for entry of a looptaker orrotary hook beak 34. The thread handling, work piercing and Work feedingdevices described thus far are constructed and arranged in aconventional manner and form no part of the present invention which isdirected more particularly to the means for interlocking the needlethread 28 with a locking thread 36 as will now be described. It willalso be appreciated that for purposes of the present invention Work feedmay be accomplished either continuously or intermittently by the workclamp, the awl, the needle or a combination of these.

i For interlocking the threads 28, 36 there is provided a looptaker body42 rotatably mounted on a supporting plate 44- by means of thin-raceball bearings 46. The beak 34 is integral with the body 42 which at itsouter end is connected to an annular pulley 48 providing a centralpassage for replenishment of a locking thread supply 50 as will beexplained. The central opening of the pulley 48 is counterbored at itsouter end and the inner end of the pulley is of reduced diameter toclamp the inner races of the bearings 46 against a shoulder on the body42, clamping pressure being applied by screws 52 passing loosely throughthe pulley and engaging the threads 'of'tapped holes in the looptakerbody. The outer races of the bearings 46 are seated in a counterboredopening in the plate 44 and are clamped therein by a thin retainer 54which coincides in shape with the plate 44 and is secured to the plateby means of screws one of which is shown at 56 in FIG. 3.

Fitted inside the loopt-aker body 42, as best shown in FIGS. 3 to 5inclusive, is a cup shaped thread case 58 formed with an interruptedflange 60 which engages a guideway 62 machined partly in the looptakerbody and complemented by a portion 64 formed in an arcuate keeper 66.The thread case in the looptaker assembly is free to remain stationaryas the looptaker is rotated about it. The keeper 66 is pinned to thebody 42 by a dowel 68 and retained in position by three screws 70.

The thread case 58 includes an end wall surface 72 and an integralperforated stud 74. A retainer nose 76 formed with a cylindrical shank78 is received loosely within the stud 74 and is held in place by ascrew 8t) having an enlarged slotted head which, with the outside of thestud 74, serves as a guide and retainer for a locking thread spool 82.The nose 76 is tapered from a thin section coinciding with the centralportion of the thread case to a section of maximum thickness at theeriphery of the thread case. In the thickest portion there is formed anopening in which is received a ball 84 backed by a compression spring86. The ball 84 enters a spherical depression or socket 88 in thesurface 72, the ball and socket comprising a detent arrangement whichcooperates with means to be described to hold the thread case againstrotation with the looptaker under normal operating conditions butreleases the thread case to revolve with the looptaker in the event thatan obstruction causes binding of the thread case to the looptaker.

Passing over the pulley 48 is a flexible cogged belt 90 driven by aflanged pulley 92 mounted on an inclined intermediate shaft 94. The cogson the belt 90 enter grooves in the pulley 48 and 92 to maintain theproper time relationship between the looptaker and the otherinstrumentalities of the machine. At its innerend the shaft 94 carries abevel gear pinion 96 meshing with a gear 98 keyed to the sewing shaft12. The tooth ratio of the pinion 96 and the gear 98 is 1 to 3 so thatthe beak 34 of the looptaker is driven through three completerevolutions for each revolution of the sewing shaft 12.

The support for the shaft 94is designed both for ease and economy ofmanufacture and for. convenience and accessibility for maintenance. Tothis end the frame is formed with an integral hollow extension 100terminating at its outer end in a shelf 102, to which the plate 44 isfixedly secured. Received withinthe extension 100 is a headed sleeve1414 in which the shaft is journaled and which may be readily removedfrom the machine for replacement of component parts and for adjustment.

The shaft 94 is rotatable at its inner end in a double row thrust ballbearing 106, having a snap ring 1% entering a groove in its outer raceto act as a shoulder. The outer race is fixedly secured in the sleeve104by a clamp ring 110 through which loosely pass screws 112 engaging thethreads of tapped holes in the sleeve. At its outer end' the shaft 94rotates in a ball bearing 114, the outer race of which is pressed intothe bore of the sleeve 104. The inner races of the bearings 106,. 114are clamped in position on the shaft 94 by a tubular spacer 116 and anut118 threaded on the outer end of the shaft. Screws 120 clamp the sleeve104 to the frame extension 106 and are quickly removed for Withdrawal ofthe sleeve in order to replace or adjust the pinion 96, or the bearings1G6 and 114.

The thread case is retained against rotation with the looptaker by anupward projection 122, seen in FIGS. 1 and 2, which engages a slopinglead surface 124 of the nose 76, best seen in FIGS. 1 and 5,. Definedbetween the nose and the projection 122 is a tapered' passage 125 (FIG.5 into which the needle loop enters after having been passed about thethread case in order to be released from the case as the needle loop isbeing contracted by conventional takeup action. In order to retain thethread case against rotation in the reverse or clockwise direction, asseen in FIG. 1, in the event that the operator should turn the shaft 12manually in the reverse direc tion, a retainer finger 126 is fixedlysecured to the underside of the shelf 162, and engages a generallyvertical surface 128 opposite the surface 124 on the retainer nose. Thenormal spacing between" the finger 126 and the surface 128 is sufficientto permit a slight oscillatory motion of the thread case as the needleloop is drawn between the surfaces 122 and 124.

' The nose 76 as seen in FIGS. 2 and 3, is formed with a concavedifferentially tapered back surface 130. Such a configuration isadvantageous in affording a high degree of control over the flow of theneedle loop as will be appreciated from the showing of FIGS.'1 and 4 inwhich the forward leg of the needle loop at the time of entry of thebeak 34 into the loop is identified by the reference character A and therearward leg at the same time is over the open front of the case so thatthe loop isgiven A a half twist in the process of passing over thethread case. As will be seen in FIG. 1 which represents maximumexpansion of the needle loop theleg B here de-.

noted as B has assumed a chordal position across the open end of thethreadcase and the leg A here. denoted as A extends from the looptakerthroat 136 over the ledge 134. drops off the ledge 134 and because ofthe shape of the back surface 139 of the nose continues to lag behindthe leg B. The relative positions of the legs after the leg A, hasdropped off the ledge 134, are illustrated in FIG.

4 in which symbols B and A are applied to the legs extending over theopen and closed ends of the thread case respectively at a time whentheneedle loop is s-tarting to be contracted by takeup' action. Shown asA and B in FIG. 4 are the legs A and B; after the loop has been furthercontractedby the takeup and as the needle thread has advanced into thepassage between the surfaces 122 and 124. Because there remains a degreeof friction'in the mounting of the flange 60' within the guideway 62, 64the thread case tends to rotate with the looptaker and this tendencynormally maintains the nose 76 in abut-v ment with the projection. 122.With continued takeup 1 action after the needle loop has passed theposition A 1 B the thread passes between the finger 126 and thesurneedle loop surrounds the locking thread 50 and the loop I As thebeak 34 continues to rotate, the leg A continues to contract for settingthe thus-formed thread I lock within the outsole 14. t

I The surface affords a higher degree of uniformity in the timing of theneedle loop release from the beak 34 p This improvement in j looprelease timing enhances the accuracy of thread meas than has heretoforebeen possible.

urement in the present machine and results in more uniform placement ofthread locks in the work piece. It

the needle loop after the beak 34 has moved past the position of maximumloop extension and theleg A has? fallen off the ledge 134. Anotheradvantage inherent in the contour of the surface'130 is the fact thatthe leg A lies over a minimum thickness of the nose 76 so that in efiectthe presence of the nose does not add appreciably v to the threadrequirement of the loop and consequently has an insignificant effect onthread wear attributable to repeated passage of successive threadportions through the Work piece.

Although the present thread case retaining arrangement will functionsatisfactorily with a split raceway mounted, gear-driven looptaker whenthe machine is new and there is little eccentricity or looseness in thelooptaker motion or in the support of the thread case within thelooptaker, special care is necessary to minimize thread abrasion andwear as the needle loop passes between the surface 122 and theprojection 124. As has already been generally indicated, anyeccentricity in the rotation of the looptaker is translated into areciprocating, sawing motion of the nose 76 against the projection 124.Accordingly, the bearings 46 upon which the looptaker is rotatablysupported and the flexible shock absorbing upwardly biasing character ofthe drive provided by the belt 90 by assuring continued concentricity oflooptaker rotation over an extended useful life contribute materially tothe success of the present thread case retainer arrangement over anextended period of machine utilization. In addition, because thebearings 46 may include a quantity of sealed-in lubricant, wear isminimized without the risk of soiling the work piece.

Other advantages of the present construction may be seen from FIG. 1 inwhich it will be observed that the axis of rotation of the looptaker isdisplaced laterally from the plane of the needle and the lower corner ofthe plate 44 has been cut away to provide an unobstructed view of thesewing point to the operator without increasing the thread requirementof the needle loop. Another advantage lies in the fact that the line ofcenters of the pulleys 43 and 92 is inclined approximately 45 from thevertical, thereby removing the shaft 94 and the gearing 96, 98 from themost congested area directly behind the sewing point, an importantfactor in simplifying actuating connections for the needle, the awl andthe work clamping instrumentalities, particularly in a single shaftmachine in which the present invention is embodied.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. In a lock stitch shoe outsole sewing machine having a work support,stitch forming and thread manipulating instrumentalities including ahook needle for withdrawing from the work, carrying loops of needlethread, a cup shaped thread case having an inner end wall and enclosinga supply of locking thread, and a rotary looptaker formed with a beakfor entering and passing the needle thread loops about the thread case,the combination of .a nose on the outside of the end Wall of the threadcase, fixed abutment means engaging the nose to retain the thread caseagainst rotation, and driving means including a cogged belt forcontinuously rotating the looptaker in timed relation with the needleand other stitch forming and thread manipulating instrumentalities.

2. In a lock stitch shoe outsole sewing machine having a sewing shaft, awork support, stitch fonrning and thread manipulating instrumentalitiesincluding a curved hook needle for withdrawing from the work, carryingloops of needle thread, a cup shaped thread case having an inner endwall and enclosing a supply of locking thread, and a rotary looptakerformed with a beak for entering and passing the needle thread loopsabout the thread case, the combination of a nose on the outside of theend wall of the thread case, fixed abutment means engaging the nose toretain the thread case against rotation in either direction, an inclinedshaft driven by the sewing shaft and a cogged belt for continuouslyrotating the looptaker in timed relation to the sewing shaft.

3. In a lock stitch shoe outsole sewing machine having a sewing shaft, awork support, stitch forming and thread manipulating instrumentalitiesincluding a curved hook needle for withdrawing from the work, carryingloops of needle thread, a cup shaped thread case having an inner endwall and enclosing a supply of locking thread, and a rotary looptakerformed with a beak for entering and passing the needle thread loopsabout the thread case, the combination of a nose on the outside of theend wall of the thread case, abutment means engaging the nose to retainthe thread case against rotation and defining with the nose a taperedpassage for the loops, an inclined shaft driven by the sewing shaft anda cogged belt connecting the inclined shaft and the lo-optaker forcontinuously rotating the looptaker in timed relation to the sewingshaft.

4. In a lock stitch shoe outsole sewingmachine having a horizontal worksupport, stitch forming and thread manipulating instrumentalitiesincluding a hook needle for withdrawing from the work, carrying loops ofneedle thread, a cup shaped thread case having an end wall and enclosinga supply of locking thread, and a rotary looptaker formed with a beakfor entering and passing the needle thread loops about the thread case,the combination of a nose on the outside of the end wall of the threadcase, detent means releasably coupling the nose to the thread case underconditions of normal torque and abutment means engaging the nose toretain the thread case against rotation.

5. In a lock stitch s-h-oe outsole sewing machine having a horizontalwork support, stitch forming and thread manipulating instrumentalitiesincluding a hook needle for withdrawing from the work, carrying loops ofneedle thread, a cup shaped thread case having an end wall and enclosinga supply of locking thread, and a rotary looptaker formed with a beakfor entering and passing the needle thread loops about the thread case,the combination of a nose pivotally mounted concentrically with theloopt-aker on the outside of the end Wall of the thread case, detentmeans releasably coupling the nose member to the thread case underconditions of normal torque and abutment means engaging the nose toretain the thread case against rotation.

6. In a lock stitch shoe outsole sewing machine having a horizontal worksupport, stitch forming and thread manipulating instrumentalitiesincluding a hook needle for withdrawing from the work, carrying loops ofneedle thread, a cup shaped thread case having an end wall and enclosinga supply of locking thread, and a rotary looptaker formed with a beakfor entering and passing the needle thread loops about the thread case,the combination of a nose pivoted on the outside of the end wall of thethread case, detent means including a socket formed in the end wall anda spring pressed ball in the nose engaging the socket for releasablycoupling the nose to the thread case under conditions of normal torqueand abutment means engaging the nose to retain the thread case againstrotation.

7. In a lock stitch shoe outsole sewing machine having a horizontal worksupport, stitch forming and thread manipulating instrumentalitiesincluding a hook needle for withdrawingfro-rn the work, carrying loopsof needle thread, a cup shaped thread case having an end wall andenclosing a supply of locking thread, and a rotary looptaker formed witha beak for entering and passing the.

needle thread loops about the thread case, the combination of a nosereleasably coupled to the outside end wall of the thread case, the nosebeing formed with a concave surface over which the needle loop flows inbeing passed about the thread case, and an abutment means engaging thenose to retain the thread case against rotation.

8. In a lock stitch shoe outsole sewing machine having a horizontal worksupport, stitch forming and thread manipulating instrumentalitiesincluding a hook needle for Withdrawing from the work, carrying loops ofneedle thread, a cup shaped thread case having an end wall and enclosinga supply of locking thread, and a rotary looptaker formed with a beakfor entering and passin the needle thread loops about the thread case,the combination of a nose releasably coupled to the outside end wall ofthe thread case, the nose being formed with a concave surface over whichthe needle loop flows in being passed about the thread case and asloping lead surfiace "and a projection engaging the nose to retain thethread case against rotation and defining with the sloping leadsurescape from the thread case.

. .o References fitedin the file of this patent UNITED STATES PATENTS2,049,369 5 2,780,188 Seh'aefer ,et a1 Feb. 5, 1957 3,038,429 Kettereret 'al June 12, 1962 Gouldbourne et a1. July 28, 1936

1. IN A LOCK STITCH SHOE OUTSOLE SEWING MACHINE HAVING A WORK SUPPORT,STITCH FORMING AND THREAD MANIPULATING INSTRUMENTALITIES INCLUDING AHOOK NEEDLE FOR WITHDRAWING FROM THE WORK, CARRYING LOOPS OF NEEDLETHREAD, A CUP SHAPED THREAD CASE HAVING AN INNER END WALL AND ENCLOSINGA SUPPLY OF LOCKING THREAD, AND A ROTARY LOOPTAKER FORMED WITH A BEAKFOR ENTERING AND PASSING THE NEEDLE THREAD LOOPS ABOUT THE THREAD CASE,THE COMBINATION OF A NOSE ON THE OUTSIDE OF THE END WALL OF THE THREADCASE, FIXED ABUTMENT MEANS ENGAGING THE NOSE TO RETAIN THE THREAD CASEAGAINST ROTATION, AND DRIVING MEANS INCLUDING A COGGED BELT FORCONTINUOUSLY ROTATING THE LOOPTAKER IN TIMED RELATION WITH THE NEEDLEAND OTHER STITCH FORMING AND THREAD MANIPULATING INSTRUMENTALITIES.